Fiber insulator and method of making the same



Nov. 6, 1928.

E. BURKE FIBER INSULATOR AND METHOD OF MAKING THE sAME Filed Sept. 11, 1925 giaventur nunlflull'e The result, as I have attempted to illustrate in Fig. 6, is an impregnated rough formed blank which isthoroughly impregnated and from which the water has been entirely removed. I

,The article in this condition I have indicated at P. It is taken while still hot and subjected to a die forging under a considerable pressure. This produces an article as indicated at I Fig. 7, which is formed true to the shape desired. In the form shown, it is provided with an axial boss i on its upper portion and a recess 6 on its lower portion. It may be formed with any number of ribs as at 2' according to the type desired.

Such an article when cooled and allowed to harden provides an insulating unit which is capable of being worked to give it mechanical bondings such as the threadings S indicated in Fig. 8. These threadings may be milled or otherwise cut in the insulator and will be found to have ample strength for any connection desired, whether they be metallic trimmings or whether they be inter-unit bondings. Such cut surfaces are capable of a very strongcement, as by the impregnating compound itself, or by other cementitious material, and where such threaded parts on the insulator units arebrou ht together as in multiple petticoat types and so cemented, the insulator becomes practically a unitary arti cle substantially homogeneous throughout.

In practice the impregnation is carried on for two to three days to secure a very complete permeation and a very complete extraction of the water. The impregnating compound may be proportioned so as to have any desired melting point in the usual manner known to thoseskilled in the art. Insulators so prepared have a very high electric resistance and may beformed in the most approved pattern and design. Furthermore, they are capable of multiple assembly so as to make possible an insulator of any desired resistance which can be built up even on the job'and which when built up is a strong and serviceable article which will not only withstand the incidents ofordinary lineservice, but which will even withstand such abuse as sniping or other attempts at breakage.

Insulators so formed and of such strength may be shipped and handled with the great est freedom in sharp contra-distinction to the expensive barrel packing necessary, for porceall. without departing from the spirit of my invention.

What I therefore claim and desire to se cure by Letters Patent is:

1. The method of making petticoat insulators.which consists in preparing a. blank of wet laid fibrous stock, in rough shaping said blank while moist, in drying the rough shaped blank, in impregnating the blank with a dielectric thermo-plastic and die finishing under pressure.

'2. Themethod of making petticoat insulators whichconsists in preparing a blank of wet laid fibrous stock, in rough shaping said blank while moist, in drying the rough shaped blank, in impregnatingjheblank with a di-' electric thermo-plastic and die finishing under pressure and intool fitting for as-' sembl 3. g compressed fiber insulator of wet laid fibrous stock having a transverse fiber trend and impregnated with a dielectric thermo-plastic. q

In testimony whereof afiix my signature.

- EDMUND BURKE. 

